The present invention relates to a method for detecting tampering during media migration from one WORM medium to another, and more specifically, this invention relates to a method for detecting a change in data when the data is migrated through tape cartridges over generations.
Migration of data between recording media is essential for long-term storage (archiving) over a long period of time, for example, 100 years. Because of technical innovations in hardware and software, data migration every three to five years is recommended. Typical recording media for archiving are tape cartridges. Examples of tape drives for tape cartridges include Linear Tape Open (LTO) tape drives and the IBM® Enterprise tape drive model TS1130. Even though such tape drives, recording media, and the like change over generations, data recorded thereon should maintain an ability to be migrated to a current medium and still be readable.
It is also a goal of data storage to prevent crimes in which persons having access rights to data illegally rewrite the data, such as tampering of research data and rewriting of books containing financial information. Such anti-data tampering is currently a big issue with data storage.
In tape drives, Write Once Read Many (WORM) media are used as tools for preventing tampering of data. WORM media are tape cartridges where data, once written, cannot be updated or erased. Similar to normally updatable and erasable media, WORM media are physically rewritable because data is magnetically recorded thereon. Persons who are familiar with the WORM format are able to rewrite data in an undetectable manner at the time of reading. Therefore, tape drives have a mechanism for detecting if persons have maliciously tampered with the firmware of the tape drives and updated or erased data in WORM media.
Some conventional attempts at protecting data from tampering include presetting WORM attributes in media to prevent data written to a migration destination from being updated during migration, and, if a migration source medium is a WORM medium, a WORM medium is also selected as a migration destination medium.
Accordingly, a conventional tape drive is not sufficient to prevent data from being tampered with or deleted during migration. For example, conventional techniques do not guarantee that data that is initially written in a migration destination medium during migration from one WORM medium to another is the same as the data in the source medium.
Therefore, it would be beneficial to provide a method for detecting tampering during media migration from one WORM medium to another, and a storage device capable of such detection.